Select the appropriate options and complete the following paragraph.
( organic farming, humus, oxidation, increase, pesticides, fertilizers, nitrogen, biomagnification, decrease)
The uppermost layer of soil is made up of ---that is essential in agriculture. Essential elements like ___ , phosphorous and potassium need to be made.available to the crop plants. Chemicals used in agriculture, __ _ the fertility of soil. Use of ___ like DDT 1iave also. proved to be dangerous, since the poison enters the food-web and causes problems due to -,-----of the compound. To overcome these problems, farmers are opting for the practice of ___ .

Explanation

The uppermost layer of soil is made up of humus that is essential in agriculture. Essential elements like nitrogen, phosphorous and potassium need to be made available to the crop plants. Chemicals used in agriculture, decrease the fertility of soil. Use of pesticides like DDT have also proved to be dangerous, since the poison enters the food-web and causes problems · due to biomagnification of the compound. To overcome these problems, farmers are opting for t~tice of organic farming.